03.序列化二叉树

题目

请实现两个函数，分别用来序列化和反序列化二叉树。

实现

public class Codec {

    // Encodes a tree to a single string.
    public String serialize(TreeNode root) {
        if(root == null){
            return "#!";
        }
        String str = root.val + "!";
        str += serialize(root.left);
        str += serialize(root.right);
        return str;
    }

    // Decodes your encoded data to tree.
    public TreeNode deserialize(String data) {
        String[] values = data.split("!");
        Queue<String> queue = new LinkedList<String>();
        for(int i = 0; i < values.length; i++){
            queue.offer(values[i]);
        }
        return recordPreOrder(queue);
    }

    public TreeNode recordPreOrder(Queue<String> queue){
        String value = queue.poll();
        if("#".equals(value)){
            return null;
        }
        TreeNode node = new TreeNode(Integer.valueOf(value));
        node.left = recordPreOrder(queue);
        node.right = recordPreOrder(queue);
        return node;
    }
}